Question about AM335x SoC supported NAND flash

Question about AM335x SoC supported NAND flash

[Ezequiel García]

Hi guys,

We're developing a custom AM335x-based board, which is meant to boot from NAND.

The flash device is a Micron MT29F8G08ABABA NAND. This device is ONFI-compliant
and has 4 KiB page size, 512 KiB block size.

Accessing it from U-Boot and Linux works just fine, apparently in ECC BCH8 mode.

However, we cannot get the SoC to boot from NAND. We've double-checked
the hardware
and the SYSBOOT, but still no luck with it.

So, I thought about asking here, in case this device is (for some
reason) not supported by the
ROM code booting. Maybe someone already struggled with this and has
some idea to suggest?

Thanks!

PS: I'm sending this a to few developers I remember to have worked on this SoC.
Hope you don't mind!
-- 
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar

Re: Question about AM335x SoC supported NAND flash

[Daniel Mack]

On 02/19/2014 05:04 PM, Ezequiel García wrote:
> However, we cannot get the SoC to boot from NAND. We've double-checked
> the hardware
> and the SYSBOOT, but still no luck with it.
> 
> So, I thought about asking here, in case this device is (for some
> reason) not supported by the
> ROM code booting. Maybe someone already struggled with this and has
> some idea to suggest?

We're booting that SoC from an 8-bit NAND, connected to GPMC_CSN0.
SYSBOOT[11:10] is 00b.

The kernel output reads like this:

[    1.320533] nand: device found, Manufacturer ID: 0x98, Chip ID: 0xda
[    1.327280] nand: Toshiba NAND 256MiB 3,3V 8-bit
[    1.332112] nand: 256MiB, SLC, page size: 2048, OOB size: 64
[    1.338077] nand: using OMAP_ECC_BCH8_CODE_HW ECC scheme
[    1.344122] 9 ofpart partitions found on MTD device omap2-nand.0

I wasn't around for early boot-strapping of the platform, so I'm not
aware of any typical pitfalls.

If you want to compare other details between our platforms, let me know.


HTH,
Daniel

RE: Question about AM335x SoC supported NAND flash

[Gupta, Pekon]

Hi Ezequiel,

>From: Ezequiel García [mailto:ezequiel@vanguardiasur.com.ar]
>
>Hi guys,
>
>We're developing a custom AM335x-based board, which is meant to boot from NAND.
>
>The flash device is a Micron MT29F8G08ABABA NAND. This device is ONFI-compliant
>and has 4 KiB page size, 512 KiB block size.
>
>Accessing it from U-Boot and Linux works just fine, apparently in ECC BCH8 mode.
>
>However, we cannot get the SoC to boot from NAND. We've double-checked
>the hardware
>and the SYSBOOT, but still no luck with it.
>
It's a 4K pagesize device with OOBsize=128, so ROM code expects BCH16 ECC scheme
to boot SPL. Though I have locally tested BCH16 support for both u-boot and kernel,
And even booted end-to-end using BCH16 on beaglebone with 4K page NAND cape,
But that's all locally.. 
Many prior dependent patches are still awaiting acceptance in mainline list.

For BCH16 u-boot configs (but driver support is still lacking in mainline u-boot):
[1] https://processors.wiki.ti.com/index.php/Linux_Core_NAND_User%27s_Guide#ECC_schemes_support


with regards, pekon

Re: Question about AM335x SoC supported NAND flash

[Ezequiel García]

Pekon,

On 19 February 2014 14:55, Gupta, Pekon <pekon@ti.com> wrote:
[..]
>>
>>Accessing it from U-Boot and Linux works just fine, apparently in ECC BCH8 mode.
>>
>>However, we cannot get the SoC to boot from NAND. We've double-checked
>>the hardware
>>and the SYSBOOT, but still no luck with it.
>>
> It's a 4K pagesize device with OOBsize=128, so ROM code expects BCH16 ECC scheme
> to boot SPL. Though I have locally tested BCH16 support for both u-boot and kernel,
> And even booted end-to-end using BCH16 on beaglebone with 4K page NAND cape,
> But that's all locally..
> Many prior dependent patches are still awaiting acceptance in mainline list.
>

Ah... so that would explain our complete failure.

Could you send me some draft patches or event just the entire driver
or at least point me to some git repo?

This issue is currently blocking us from shipping the board to my office
so we can continue with the rest of the broad bring-up.

Huge thanks for your answer! I almost went crazy with this :-)
-- 
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar